One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,15,17)(11,18,21,16)(12,13,22,14)(19,23,24,20)(25,26,29,31)(27,35,36,49)(28,40,41,33)(30,43,37,34)(32,45,44,39)(38,52,50,48)(42,47,51,55)(46,53,54,56)(1,2)(3,7)(4,6)(5,8)(9,11,15,21)(10,16,17,18)(12,19,22,24)(13,20,14,23)(26,31)(27,36)(33,40)(34,43)(38,50)(39,45)(47,55)(53,56)(1,3)(2,5)(4,8)(6,7)(9,12)(10,13)(11,19)(14,17)(15,22)(16,20)(18,23)(21,24)(25,27,37,45,29,36,30,39)(26,32,43,49,31,44,34,35)(28,38,51,56,41,50,42,53)(33,46,55,52,40,54,47,48)(3,8)(5,7)(9,13,15,14)(10,12,17,22)(11,20,21,23)(16,19,18,24)(25,28,29,41)(26,33,31,40)(27,38,36,50)(30,42,37,51)(32,46,44,54)(34,47,43,55)(35,48,49,52)(39,53,45,56)(2,6)(5,7)(9,14,15,13)(10,12,17,22)(11,20,21,23)(16,24,18,19)(28,41)(33,40)(38,50)(42,51)(46,54)(47,55)(48,52)(53,56)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.